scholarly journals The transcript release factor PTRF augments ribosomal gene transcription by facilitating reinitiation of RNA polymerase I

2001 ◽  
Vol 29 (2) ◽  
pp. 423-429 ◽  
Author(s):  
P. Jansa
Keyword(s):  
Rna Polymerase ◽  
Gene Transcription ◽  
Ribosomal Gene ◽  
Rna Polymerase I ◽  
Release Factor ◽  
Polymerase I

scholarly journals Association of DNA topoisomerase I and RNA polymerase I: a possible role for topoisomerase I in ribosomal gene transcription

Chromosoma ◽  
1988 ◽  
Vol 96 (6) ◽  
pp. 411-416 ◽  
Author(s):  
Kathleen M. Rose ◽  
Jan Szopa ◽  
Fu-Sheng Han ◽  
Yung-Chi Cheng ◽  
Arndt Richter ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Gene Transcription ◽  
Topoisomerase I ◽  
Ribosomal Gene ◽  
Rna Polymerase I ◽  
Dna Topoisomerase I ◽  
Dna Topoisomerase ◽  
Polymerase I

Identification of two steps during Xenopus ribosomal gene transcription that are sensitive to protein phosphorylation

1994 ◽  
Vol 14 (3) ◽  
pp. 2011-2020
Author(s):  
P Labhart
Keyword(s):  
Protein Kinase ◽  
Rna Polymerase ◽  
Protein Phosphorylation ◽  
Gene Transcription ◽  
Okadaic Acid ◽  
Protein Phosphatase ◽  
Transcription Initiation ◽  
Ribosomal Gene ◽  
Rna Polymerase I ◽  
Polymerase I

Protein kinase(s) and protein phosphatase(s) present in a Xenopus S-100 transcription extract strongly influence promoter-dependent transcription by RNA polymerase I. The protein kinase inhibitor 6-dimethyl-aminopurine causes transcription to increase, while the protein phosphatase inhibitor okadaic acid causes transcription to decrease. Repression is also observed with inhibitor 2, and the addition of extra protein phosphatase 1 stimulates transcription, indicating that the endogenous phosphatase is a type 1 enzyme. Partial fractionation of the system, single-round transcription reactions, and kinetic experiments show that two different steps during ribosomal gene transcription are sensitive to protein phosphorylation: okadaic acid affects a step before or during transcription initiation, while 6-dimethylaminopurine stimulates a process "late" in the reaction, possibly reinitiation. The present results are a clear demonstration that transcription by RNA polymerase I can be regulated by protein phosphorylation.

scholarly journals Identification of two steps during Xenopus ribosomal gene transcription that are sensitive to protein phosphorylation.

1994 ◽  
Vol 14 (3) ◽  
pp. 2011-2020 ◽  
Author(s):  
P Labhart
Keyword(s):  
Protein Kinase ◽  
Rna Polymerase ◽  
Protein Phosphorylation ◽  
Gene Transcription ◽  
Okadaic Acid ◽  
Protein Phosphatase ◽  
Transcription Initiation ◽  
Ribosomal Gene ◽  
Rna Polymerase I ◽  
Polymerase I

Protein kinase(s) and protein phosphatase(s) present in a Xenopus S-100 transcription extract strongly influence promoter-dependent transcription by RNA polymerase I. The protein kinase inhibitor 6-dimethyl-aminopurine causes transcription to increase, while the protein phosphatase inhibitor okadaic acid causes transcription to decrease. Repression is also observed with inhibitor 2, and the addition of extra protein phosphatase 1 stimulates transcription, indicating that the endogenous phosphatase is a type 1 enzyme. Partial fractionation of the system, single-round transcription reactions, and kinetic experiments show that two different steps during ribosomal gene transcription are sensitive to protein phosphorylation: okadaic acid affects a step before or during transcription initiation, while 6-dimethylaminopurine stimulates a process "late" in the reaction, possibly reinitiation. The present results are a clear demonstration that transcription by RNA polymerase I can be regulated by protein phosphorylation.

scholarly journals Feedback regulation of vitamin D metabolism by 1,25-dihydroxycholecalciferol

1977 ◽  
Vol 164 (1) ◽  
pp. 83-89 ◽  
Author(s):  
K W Colston ◽  
I M A Evans ◽  
T C Spelsberg ◽  
I MacIntyre
Keyword(s):  
Vitamin D ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Gene Transcription ◽  
Subcutaneous Administration ◽  
Feedback Regulation ◽  
Rna Polymerase I ◽  
Hydroxylase Activity ◽  
Vitamin D Metabolism ◽  
Polymerase I

Many factors influence the production of 1,25(OH)2D3 (1,25-dihydroxycholecalciferol) by the kidney. One important factor seems to be feedback regulation by 1,25(OH)2D3 itself. Administration of 1,25(OH)2D3 to vitamin D-deficient chicks abolishes renal 25(OH)D3(25-hydroxycholecalciferol)1-hydroxylase activity and induces the appearance of 25(OH)D3 24-hydroxylase activity. It is likely that these effects are mediated via a nuclear effect, as they are prevented by pretreatment with actinomycin D and alpha-amanitin. Further, 1,25(OH)2D3 has a marked effect on gene transcription in the kidney cell, as assessed by measurement of RNA polymerase activities. RNA polymerase I and II activities are 80-90% inhibited by 12.5nmol of 1,25(OH)2D3 within 30min of subcutaneous administration, indicating an immediate and massive decrease in total gene transcription. By 4h RNA polymerase II activity has returned to control values, but RNA polymerase I activity is markedly enhanced. These results are consistent with the view that regulation of cholecalciferol metabolism in the kidney is associated with an effect of the active metabolite on the kidney nucleus.

Enhancers for RNA polymerase I in mouse ribosomal DNA

1990 ◽  
Vol 10 (9) ◽  
pp. 4816-4825
Author(s):  
C S Pikaard ◽  
L K Pape ◽  
S L Henderson ◽  
K Ryan ◽  
M H Paalman ◽  
...  
Keyword(s):  
Dna Binding ◽  
Rna Polymerase ◽  
Gene Promoter ◽  
Intergenic Spacer ◽  
Regulatory Elements ◽  
Ribosomal Gene ◽  
Rna Polymerase I ◽  
Functional Consequences ◽  
In Trans ◽  
Polymerase I

The intergenic spacer of the mouse ribosomal genes contains repetitive 140-base-pair (bp) elements which we show are enhancers for RNA polymerase I transcription analogous to the 60/81-bp repetitive enhancers (enhancers containing a 60-bp and an 81-bp element) previously characterized from Xenopus laevis. In rodent cell transfection assays, the 140-bp repeats stimulated an adjacent mouse polymerase I promoter when located in cis and competed with it when located in trans. Remarkably, in frog oocyte injection assays, the 140-bp repeats enhanced a frog ribosomal gene promoter as strongly as did the homologous 60/81-bp repeats. Mouse 140-bp repeats also competed against frog promoters in trans. The 140-bp repeats bound UBF, a DNA-binding protein we have purified from mouse extracts that is the mouse homolog of polymerase I transcription factors previously isolated from frogs and humans. The DNA-binding properties of UBF are conserved from the mouse to the frog. The same regulatory elements (terminators, gene and spacer promoters, and enhancers) have now been identified in both a mammalian and an amphibian spacer, and they are found in the same relative order. Therefore, this arrangement of elements probably is widespread in nature and has important functional consequences.

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